Each of the below U.S. Patents and Applications is hereby incorporated herein by reference.
U.S. Pat. No. 4,776,818 discloses an electrical control system for trimming a pair of stern motors or drives mounted side-by-side on a boat. The two drives are both jointly and independently movable through a plurality of trim positions. The system includes two trim cylinders, each coupled to one associated drive, to move its associated drive to different trim positions both jointly as well as independently of each other. An operator controlled mechanism energizes and de-energizes the two trim cylinders simultaneously to jointly vary the trim position of the two drives. Two lines, each coupled at its first end to one associated drive, independently detect both the angular trim position of its associated drive with respect to the other drive as well as detects the trim position of the two drives jointly. Detection apparatus is coupled to the second end of each of the two lines and is responsive to the two lines when the two drives are not in the desired equal trim position with respect to each other for controlling switches to inactivate one of the trim cylinders and thereby moves the other of the trim cylinders with respect to the inactivated one trim cylinder until the desired equal trim position is achieved between the two drives.
U.S. Pat. No. 4,861,292 discloses a system for optimizing the speed of a boat at a particular throttle setting that utilizes sensed speed changes to vary the boat drive unit position vertically and to vary the drive unit trim position. The measurement of boat speed before and after an incremental change in vertical position or trim is used in conjunction with a selected minimum speed change increment to effect subsequent alternate control strategies. Depending on the relative difference in before and after speeds, the system will automatically continue incremental movement of the drive unit in the same direction, hold the drive unit in its present position, or move the drive unit an incremental amount in the opposite direction to its previous position. The alternate control strategies minimize the effects of initial incremental movement in the wrong direction, eliminate excessive position hunting by the system, and minimize drive wait repositioning which has little or no practical effect on speed.
U.S. Pat. No. 5,263,432 discloses adjustment of a power boat's trim tabs that is automated throughout all phases of the operation of the boat. The boat's speed and/or the revolutions of its engine(s) are sensed and used by electronic circuits, including microprocessor-based circuits, to control prime movers, typically hydraulic pumps, in order to move the trim tabs to their optimal position. In one embodiment the boat's speed is sensed by a speedometer. Below a first predetermined speed, the boat's trim tabs are moved full down. Above a second, higher, predetermined speed the trim tabs are moved full up. In another embodiment the trim tabs are further adjusted in and about their up position, and while the boat is on-plane, so as to optimize the performance of the boat. The boat's on-plane performance is monitored by a speedometer or, preferably, by one or more tachometers. After the boat has exceeded the first predetermined speed, after the trim tabs have been initially adjusted to their full up positions, and after the speedometer or tachometer(s) is (are) continuously reading values within some small, preset, range, the trim tabs are perturbed slightly in position. The boat's throttle remains unchanged. After a settling time any effect of the changed trim tab position on the boat's performance is assessed. The trim tabs are moved in position until performance is no longer improved by further perturbations in position.
U.S. Pat. No. 5,707,263 discloses a system for a trimmable marine stern drive that shifts the trimmable range on a conventional hydraulic trim system. The system includes an enlarged cylinder anchor pin hole in the drive shaft housing, an anchor pin smaller in size than the enlarged anchor pin hole located in the drive shaft housing, and a movable trim adjustment insert that is inserted into the enlarged anchor pin hole to secure the anchor pin in a fixed position within the enlarged hole. It is preferred that the enlarged anchor pin hole be a substantially horizontal elongated hole, and that the trim adjustment insert be placed rearward of the anchor pin to position the anchor pin in a forward position, or forward of the anchor pin to locate the anchor pin in a rearward position. The invention shifts the trimmable range of the drive, while maintaining vibration isolation characteristics available in conventional hydraulic trim systems.
U.S. Pat. No. 6,007,391 discloses an automatically adjustable trim system for a marine propulsion system that provides automatic trimming of the propeller in response to increased loads on the propeller. A propulsion unit is attached to a boat transom through a tilt mechanism including a transom bracket and a swivel bracket. In a first embodiment, the transom bracket is clamped to a flexible transom which flexes in response to forces exerted on the transom during acceleration. In a second embodiment, the transom bracket is clamped to a transom bracket mounting platform that is generally parallel to and pivotally attached to the transom. A trim angle biasing mechanism is mounted between the transom and the transom bracket mounting platform for automatically adjusting the trim angle. A third embodiment includes a trim angle biasing mechanism incorporated into the transom bracket or swivel bracket. A fourth embodiment includes a spring-loaded pawl assembly between the swivel bracket and transom bracket.
U.S. Pat. No. 7,188,581 discloses a marine drive and a marine vessel and drive combination having a trim tab with a forward end pivotally mounted to a marine propulsion device.
U.S. Pat. No. 7,416,456 discloses an automatic trim control system that changes the trim angle of a marine propulsion device as a function of the speed of the marine vessel relative to the water in which it is operated. The changing of the trim angle occurs between first and second speed magnitudes which operate as minimum and maximum speed thresholds.
U.S. Pat. No. 8,457,820 discloses a method for controlling the operation of a marine vessel, subject to porpoising. The method includes sensing an operational characteristic of the marine vessel which is indicative of porpoising of the marine vessel, and responding, to the sensing of the operational characteristic with a response that is representative of the operational characteristic of the marine vessel as being indicative of the porpoising of the marine vessel.